四川省水稻高温热害时空分布特征研究

Temporal and Spatial Distribution of Heat Injury on Rice in Sichuan Province

摘要: 利用四川省103个台站1980~2015年7~8月日平均气温数据、日最高气温数据资料，采用数理统计方法统计高温热害的天数，并计算出不同等级发生的频次，以此探究四川地区水稻高温热害发生的空间分布特征；采用Morlet小波分析研究高温热害周期变化，以探究四川地区水稻高温热害发生的时间分布特征。结果表明：1) 四川省水稻高温热害集中在水稻生长期的抽穗结实期，所以灾害大部分发生在每年7、8月份，其中以7月下旬和8月上旬最为严重；2) 水稻高温热害在1980~1987年里总频次呈现出下降趋势，1988~2015年呈现出平稳上升趋势，不同等级程度的高温热害发生频次的年际变化特点与总频次变化趋势一致；3) 不同等级高温热害次数呈现了不同时间尺度的周期震荡，轻度高温热害表现为5年、10年左右的周期变化，中度高温热害以4年、10年左右的周期震荡表现显著，重度高温热害则表现出5年、16年左右的周期震荡；4) 总体来说，热害灾害与纬度和地势有明显联系，四川盆地东部附近是水稻高温热害灾害重灾区，中部从西南往东北方向发展，主要分布于泸州市、达州市、广安市、宜宾市、南充市等，每年7、8月发生次数都在2次以上。

Abstract: Based on the daily mean temperature data and daily maximum temperature data of 103 stations in Sichuan province from 1980 to 2015 in July to August, the length of high temperature heat damage duration is calculated using mathematical statistical methods. And the frequency of different levels of high temperature heat damage on rice is analyzed. The spatial distribution characteristics of rice heat damage in Sichuan area were studied by using Surfer8.0. Changes of heat cycle in high temperature are analyzed by the Morlet wavelet analysis. The spatial and temporal distribution characteristics of rice heat damage are further explored in Sichuan province. The results showed: 1) The high temperature injury on rice in Sichuan province was concentrated in the long period of the rice growth. Most of the disasters occurred in July and August. 2) The total number of heat injury showed a trend of decline in 1980 - 1987, with a steady upward trend in 1988 - 2015, and the characteristics of interannual changes at different levels of high temperature heat damage are consistent with the trend of the total occurrences. 3) The annual occurrence times at three levels of rice heat injury fluctuated in a remarkable cyclical manner i.e., slight grade fluctuated in the time scale of 5 years, about 10 years; moderate grade fluctuated significantly in 4 years, about 10 years and severe grade fluctuated in 5 years, 16 years. 4) In general, thermal disasters are obviously associated with latitude and topography; the high value area is located in the east of the Sichuan basin, and the central Sichuan region stretches from the southwest to the northeast; the heat injury occurred mainly in Luzhou, Dazhou, Guangan city, Yibin, Nanchong. The frequency of heat injury on rice is more than two times a year in these counties.